Process of treating wood to produce terpenes and wood-pulp.



W. J. HOUGH. PROGESS OF TREATING WOOD T0 PRODUCE TERPENES AND WOOD PULP. APPLICATION FILED MAY 14, 1908.

903,859. Patented Nov. 17, 1908.

TO comnmsan UNITED STATES-PATENT WILLIAM J'. none 11, or "TOLEDO, OHIO.

OFFICE,

- PROCESS OF TREATING WOOD TO PRODUCE TERPENES AND WOOD-PULP.

Specification of LettersPa' tent.

Patented Nov 17, 1908;

Application filed lilay lfi, 1908. Serial No. 432,933.

To all'whom it may concern: Be it known that I, WILLIAM J House, a

citizen of the United States, residing at To-1 ledo, in the county of Lucas and-State of Ohio, have invented certain new and usefulv Improvements in Processes of Treating.

Wood to Produce Terpenes and Wood-Pulp, of which the following is a specification.-

My inventionrelates to a process for the production of terpenes and paper pulp'from resinous wood, in one continuous operation.

The process involves the successive steps I of the removal of the terpenes, thedrying of the exhausted wood, and the reduct1on tov pulp of the same, each progressive act being.

accomplished within a digester without the handling or removal of the wood, the same remaining continuously within the digester throughout the process. I

My invention willnow be fully set forth and particularly pointed out the claims, reference being had to the'accompanying drawing forming part hereof, and illustrat' ing a suitableapparatus for carrying out p i v I boiler pressure of 50 pounds (50pounds the process.

The resinous wood, such as stumps, roots, slabs, null waste, and fallen and standing timber, is first reduced to small pieces by chipping, shaving, or any of the usual methods of preparing wood for the pulping-prom ess; Not only is it necessary to; have the wood in this condition to pulp it, but to ex-' tract the terpenes as will now be explained.

The terpenes exist in.th e resinous woodtogether with resinous acids as anoleo resin, from which the terpenes are volatilized at temperatures ranging from 155 de grees O. to 185 degrees C. However they have the property of distilling with steam, as has also a heavier oil, native-to the wood,

boiling between 185 and, 250 'degrees'C.,'and

known to commerce as pine oil. While the terpenes distil with steam a tempera ture of about 100 degrees (3., thepi'ne 'oil requires a somewhat greater degree of heat. It is impossible for steam to completely penetrate the pores'of the wood when the same is in large pieces. The wood must be .now distilwith the steam,

gester may beof any-kind, such as used in the" soda pulp industry. However, a rotary .digester, either spherical or cylindrical, is

preferred, as-I have found that this type of digester insures a complete penetration of the resmouswood by the chemical reagents used in pulping the same. Valve E is provided-at the top of the digester, said valve being connectedwith pipe M which In case the dileads to condenser T.

ester-is rotary, a suitable connection must e provided between valve E and pipe .M, and preliminary to the extraction ofthe terpenes the digesterv must be revolved to such a position that valve E is ver- 7.

tical and connection can be made with pipe Steam, preferably dry or trapped steam, is now admitted to the digester by opening the valve A. The terpenes will above, and escaping through pipe M are condensed, together with'the steam, in condenser T, and then collected.

It is preferable that the steam be of a above atmospheric pressure), as steam of this pressure is r of sulficient temperature (about :155 degrees-G.) to extract all the pine oil. A boiler pressure much greater than this should be avoided, as the steam will have a temperature that willzcause the terpenes to change into-inferior bodies and to be contaminated with malodorous, objectionable products.-

Steam of. a temperature of about 200 degrees C. will 'cause'the wood to char, wherebg the terpenes will be polluted with phenolo' and other bad-smelling hydrocarbons, rendering the'wood unfit' for pulping by reason of the charring of thec'ellulose. The terpenes are all isomerides of. the formula C H and change vfrom one class into another with slight provocation. Oil of turpentine is composed mostly of pinene, boiling at 155 degrees G.,'and when this terpene is subjected to amuch greater degree of heat, it changes into. dipentine, also a terpene, but having a boiling point of 17 8 degrees C. Consequently it is of importance to avoid steam of high pressure and high temperature. A diges'ter pressure of about 40 pounds is carried,

in order to secure rapid penetration of the chips by the steam.

The steaming of the chips continues until the terpenes cease to be volatilized, which requires about three to four hours time. The

as pointed out 75 chips are nowvery moist, and this moisture must be driven off before the chips can be reduced to pulp, as the pulping liquors such as used in the soda or sulfate process of pulping resinous wood will not penetrate the chips While in this condition, a fact well known in the art. The pulping solutions must replace the moisture in the chips, and

-. this cannot be accomplished until the chi s tening of the chips during the volatilizing operation is minimized, so that less time is required for drying. And, as is ev dent,

there is a further saving of time by intro-.

'ducing steam into drying coil Y well -before the volatilization of the terpenes is completed. A boiler pressure of not over 50 pounds should becarriedin coil Y, as

steam of much greater pressure will have a temperature that will impair the cellulose of the wood, and also result in the production of poor ter enes, as explained above.

It is to be noted thatafter the terpenes are distilled from. the wood, the chips are dried without removal of the same from the digester. During the steaming process described above, many of the terpenes are condensed. This is due to several causes, but mainly to the fact that the terpenes extracted from the bottom of the digester are' cooled while passing throu h the mass of chips above. Consequently, if the chips are now removed from the digester for the purpose of drying them, they will be found to be not only moist but stic owing to the condensed terpenes on their surfaces; and upon their removal, the chips being warm, the terpenes will be absorbed by the air, and considerable loss will i'esult. This objection is entirely overcome by the drying of the chips in t e same digester within which the terpenes have been extracted and the chips are to be pulped. By my method a stronger pulp also results, as Wlll be a parent from the explanation below. Whi e .drying the chips a large amount of the resinous acids oozes out upon the surface of the chipsalso other gelatinous gums. The chips while in this condition and warm, are extremely receptive to the alkali solution, and the cook takes place in lesstime than otherwise. Now, if the chips were removed from the digester at this step of the process, taken to another place and dried, and thereafter replaced in the-same or another digester, thechips would have an opportunity to cool during the last transfer, and re-absorption would take place. That is, the cellulose would absorb the gelatinous gums or inter-cellulose adhesive matter. A strongersolution would be necessary in consequence, to pulp it, more time would be required, and the fiber would be more or less injured, being shorter and necessarily, therefore, of impaired stren th. Aspulp resulting from resinous wood is peculiarly adapted to wrapping paper,'the strength of the pulp is of the utmost importance. The drying of the chi s without removal saves a' large amount of abor and time, also, as is self-evident; by the old methods itis necessary to empty the digester by hand or conveyer means, as it would be impossible to blow the chi s. And furthermore, the digester could not e unloaded until the ressure in the digester had fallen to that of the atmosphere, which would be a matter of some time.

After the moisture has been driven off, liquors of the usual strength used in the manufacture of wood pulp by the soda or the so called sulfate process are admitted to the digester by opening valve J After a sufiicient quantity of the pulping reagent has entered the di ester, valve J is closed. If a rotary igester is used,

valve E is disconnected from pipe M, and the digester allowed to revolve. Steam is again admitted to the digester. The steam pressure is rapidly increased to the pressure usual in making soda or sulfate pulp (90 to 110 pounds), which pressure is maintained for a period of eight to ten hours. The incrustin material is now completely dissolved, an the wood reduced to v pulp. The pressure is allowed to run down efore the end of the operation, and the pul' blown.

hat I claim is:

1. The method described, which consists in introducing resinous wood into a receptacle, volatilizing and carryin off the tergenes from the wood within t e receptacle y introducing steam into the receptacle, then, without removing the wood from the rece tacle, driving off the moisture from the woo within the rece tacle, and then, without the removal of the wood from the receptacle, making the wood into pulp within the receptacle.

- 2. The method described, which consists in introducing resinous wood into a receptacle, volatilizing'and carryin oil the terpenes from the wood within the receptacle steam is being mtroduced into the receptacle,

andthen, without the removal of the wood from the receptacle, making the wood into 10 pulp within the receptacle.

In testimony whereof I affix my signature, in presence of two witnesses.

WILLIAM J. HOUGH.

Witnesses:

'R. PEALE HERRICK, FRANK J. KENT. 

